This invention relates to internal combustion engines, and more particularly, to devices that preheat fuel for the carburetors of these engines.
It is well known that heating fuel prior to its introduction into the carburetor, increases the combustion efficiency of these engines. There are many obstacles to overcome when designing a fuel heating device. The object of these fuel heaters is to provide the carburetor with fuel that is warmed to a predetermined temperature. The heat output of the fuel heater must be adjustable to satisfy the differing amounts of fuel needed whether the car is idling or accelerating. The heater must also work within a wide range of environmental temperatures and pressures. The heat required from the heater at warm temperatures is much less than the heat required when the outside temperature is below zero.
A related problem that occurs with the use of fuel heaters is vapor lock. Vapor lock occurs when there is partial or complete interruption in the fuel flow and is caused by the formation of bubbles of vaporized gas. When this occurs, the car is virtually useless until the gas cools and the vapors return to their liquid state. If vapor lock occurs with any regularity, the fuel heater will not be accepted by the public.
The fuel heaters must also be inexpensive to manufacture and easy to install. The savings from this device occurs over a long period of time, and many people will not purchase it if there is a large initial investment. The prior art contains many attempts to overcome the problems faced when designing a fuel heater. In U.S. Pat. No. 4,146,002, issued to Quinn, on Mar. 27, 1979, the fuel is heated by passing it through helically-shaped tubing that is surrounded by engine coolant. My prior invention, U.S. Pat. No. 4,367,717, issued Jan. 11, 1983, also utilizes engine coolant to heat the fuel. In my prior invention, the fuel is passed through a heat exchanger which heats and regulates the fuel temperature as it passes into the carburetor. My prior invention, as well as many others, have numerous machined parts and are expensive to manufacture.
The prior art has demonstrated the advantages of using fuel heaters, but has not provided the public with a reliable, inexpensive fuel heater. It is accordingly clear that a need remains in the art for a fuel heater that will overcome the disadvantages of the current fuel heaters.